I just bought this old Leica iiif from a guy on eBay and I am honestly so lost. I thought I could just look through the little hole and see what I'm shooting but everything looks tiny and half the time I cant even tell if Im framing the shot right because my lens is a 35mm one and apparently the camera window is for 50mm? I dont know its all so confusing and I feel like I am wasting film. I tried looking online but there are like a million different little glass boxes you can slide into the top and they all have weird names and some cost more than the camera itself which is just insane to me. I only have about 150 bucks left after buying the camera and I just want to be able to see what I am doing when I walk around Chicago taking pictures of buildings. Im sorry if this is a really stupid question but I am just getting so frustrated trying to figure out which one actually works and wont fall off. Is there a specific brand or a cheap one that isnt total garbage for a beginner? What are the best external viewfinders for these old vintage cameras that actually fit?